Semiconductor devices incorporating superjunction structure to achieve improved electrical characteristics are known. For example, metal oxide semiconductor field effect transistor (MOSFET) devices can be incorporated with vertical or horizontal superjunction structure to optimize the on-resistance and the breakdown voltage characteristics of the transistor. As an example, Fujihira describes configurations of the lateral and vertical superjunction devices in the paper entitled “Theory of Semiconductor Superjunction Devices” (Japan Journal of Applied Physics Vol. 36, October 1997 PP 6254-6262). U.S. Pat. No. 6,097,063 also describes a vertical semiconductor device having a drift region in which a drift current flows if the drift region is in the ON mode and which is depleted if the drift region is in the OFF mode. The drift region is formed as a structure having a plurality of first conductive type divided drift regions and a plurality of second conductive type compartment regions in which each of the compartment regions is positioned among the adjacent drift regions in parallel to make p-n junctions, respectively.
Challenges remain in the design and manufacturing of superjunction semiconductor devices. These challenges include the difficulties in forming the superjunction structure, difficulties in improving manufacturability, and high product costs when epitaxial processes are used, among others. Furthermore, termination of the superjunction structure is important to ensure robust device operation.